Interlock assembly in traveling platen roller imprinting machines having settable type wheels



June 2, 1970 w. P. BARBOUR 3,515,060

INTERLOCK ASSEMBLY IN TRAVELING PLATEN ROLLER IMPRINTING MACHINES HAVING SETTABLE TYPE WHEELS Filed Jan. 31, 1968 2 Sheets-Sheet 3 R WI t I INVENTOR M1 l/AM i? filo/E5006 v June 2, 1970 w. P. BARBOUR 3,515,

INTERLOCK ASSEMBLY IN TRAVELING PLATEN ROLLER IMPRINTING MACHINES HAVING SETTABLE TYPE WHEELS Filed Jan. 31. 1968 2 SheetsSheet 2 -1 INVENTOR /4 1mm ARBOUQ 4 7 :IIIJ

ATTOR 3,515,060 Patented June 2, 1970 US. Cl. 101-45 9 Claims ABSTRACT OF THE DISCLOSURE An interlock assembly for use with imprinting devices having a source of variable data such as money amount wheels is disclosed. Between each imprinting operation all money wheels must be returned to their respective zero positions. Movement of any one of the racks respectively connected to the wheels away from the zero position tends to force a head latch into the path traveled by a shaft connected to the print head. When the head is moved from its starting position, the shaft connected thereto engages a latch release mechanism which permits the head latch to be moved into the path traveled by the shaft. However, at this time, the head has been moved past the point Where the latch is moved in the path and thus the head can be moved over the print bed. The head is then moved back over the print bed toward the latch. The latch has a cammed surface which permits the head to return to the starting position. Once the head is returned to the starting position, the latch prevents the head from being moved from that position again until all racks have been returned to the zero digit wheel position. With the return of the racks to this position, the head latch is retracted to its non-latching position and the latch release mechanism so engages the latch so as to maintain it in this position until the head is moved again from the starting position.

Background of the invention This invention relates to an interlock assembly, and in particular, to such assemblies for use with imprinting devices having a source of variable data where the data is positioned in a print bed and where the data is printed upon a document such as a sales invoice upon movement of a printing head over the bed.

Such interlock assemblies have been employed in the prior art and one such assembly is described in the US. Pat. 3,279,369, granted to William A. Wight on Oct. 18, 1966 and assigned to the assignee of the present application. The interlock assembly described therein is very effective and the operational logic thereof is quite sophisticated.

Summary of the invention A primary object of this invention is to provide an improved interlock assembly, the operational logic of which is quite simple but effective in preventing operator errors.

A further object of this invention is to provide an assembly of the above type wherein the cost of manufacture thereof is small.

Other objects and advantages of this invention will become apparent upon reading the appended claims in conjunction with the following detailed description and the attached drawing.

Brief Description of the drawing FIG. 1 is a bottom plan view of a portion of the underside of a variable data imprinter showing an illustrative embodiment of an interlock assembly of this invention.

FIG. 2 is a cross-sectional view taken along the line 22 of FIG. 1.

FIG. 3 is a cross-sectional view taken along the line 33 of FIG. 1.

FIG. 4 is a cross-sectional view taken along the line 44 of FIG. 1.

FIG. 5 is a top view of a portion of the assembly of FIG. 1 taken along the line 5-5 of FIG. 3.

FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. 1, including an associated rack mechanism and digit wheel shown in phantom lines.

Detailed description of a preferred embodiment of the invention Referring to FIGS. 1 through 6 there are shown various views of a preferred embodiment of the interlock assembly of this invention. FIG. 1 illustrates a portion of the underside of an imprinter which prints both fixed and variable data on documents such as sales invoices and the like. Further, the invention will be described in reference to an imprinter wherein the imprinter operation comprises (1) a print cycle wherein the print head moves from a starting position across the print bed to effectuate the printing of the fixed and variable data and (2) a return cycle where the head is returned in the opposite direction to the starting position without further printing. However, the invention is not limited to such imprinters.

Referring to FIG. 6 there is illustrated one digit wheel 10 of a plurality that are normally utilized on imprinters which are capable of printing variable data, such as that described in the before-mentioned US. patent. Disposed around the periphery of the digit wheel 10 are a plurality of print elements 12-30 which typically correspond to the Arabic numerals 0-9. Adjacent and connected to the digit wheel 10 is a gear face 32 having a plurality of teeth disposed around the periphery thereof. A rack 34 having a plurality of teeth on the upper surface thereof which engage the teeth of gear face 32, is adapted to rotate the digit wheel 10 to any desired position and thereby set a predetermined digit into the print bed prior to the imprinting operation. Broadly speaking, the rack 34 and gear face 32 act as a setting means for the print elements 12-30 on the digit wheel 10. The rack 32 is moved by a lever 36 which projects through the base plate 38 of the imprinting device. Indicia are provided on the upper surface of plate 38 adjacent the slot in which lever 36 moves to indicate to the operator when the predetermined digit is positioned in the print bed. Rack 34 is provided with an inclined edge 40 which typically makes an angle of 30 degrees with the vertical plane as indicated in FIG. 6, for reasons which will be described in more detail hereinafter. As shown in FIG. 6 the rack 34 is so positioned that the digit zero is set in the print bed. Also indicated in FIG. 6 is the distance the lever 36 must be removed in the direction of the arrow before the digit one will be set in the print bed. It can be further seen in FIG. 6 that before the digit one is positioned in the print bed, the inclined surface 40 of the rack will engage a complementary inclined surface 42 of an interlock glide or projecting member 44. In FIG. 1 it can be seen that the interlock glide 44 is so disposed with respect to all of the racks 3411-341 that the movement of any one of the racks away from the zero digit wheel position will effectuate an engagement on a bale shaft 48 which is secured at one end thereof to a bracket 50 connected to the underside of the plate 38. The other end of the shaft 48 is connected to an interlock bracket 52, which is also connected in fixed relation to the base plate 38, as best seen in FIG. 2. A wire bale spring 54 applies constant tension to the bale 46 so that glide 44 always stays in contact with any one of the racks which are moved from the zero digit wheel position. The vertical leg 56 of the U-shaped bale 46 is twisted into a flanged portion 58 at one end thereof as best indicated in FIGS. 1 and 2. Whenever any one of the racks is moved from the zero position, the bale 46 is so rotated around shaft 48 that the flanged portion 58 rises essentially vertically. A connecting link 60 having an inverted L-shape has its vertical leg inserted in a hole provided in the flanged portion 58 and a retaining ring 62 mounted on the link 60 prevents the link from slipping through the hole. Disposed around the link 60 is a compressionspring 64. The horizontal leg of the link 60 extends into and is connected to a connecting arm 66 which in turn is connected to a head latch 68, as best seen in FIG. 5. As will now be brought out, the head latch 68 may assume two positions, the first of which is disposed in the path of the printing head to prevent passage of the head until all racks are returned to the zero digit wheel position after an imprinting operation. When the latch 68 is moved to its second or nonlatching position, passage of the printing head is permitted. Because of the hereinbefore described connection of the racks 34a-34f to the latch 68 whenever any one of the racks is moved away from the zero digit wheel position, the latch 68 will move into its first or latching position whenever the above movement occurs while the return of all racks to the zero position will return the latch 68 to its second or non-latching position. Broadly speaking, the glide 42, bale 46, connecting link 60, and spring 64 form a first actuating means as defined in the claims.

As best seen in FIGS. 3 and 5, the print head 70 is diagrammatically shown, it being well known in this art that the head includes a roller platen diagrammatically indicated at 72 and various optional actuating mechanisms (not shown) to prevent the roller from moving over the print bed indicated by phantom lines at 74 during the return cycle of the imprinter operation. The head has mounted in its vertical side legs, one of which is indicated at 76 a respective pair of roller bearings one of which is indicated at 78, the bearing 78 being mounted on a shaft 80 which is inserted into the side leg 76. The roller bearings travel in a guide path as shown at 82 and 84 of FIG. 3. The shaft 80 extends beyond the bearing 78 as shown in FIG. and is tapered as indicated at 86 around the circumference thereof. Assuming the latch 68 is in its latching position and the head 70 is moved in the direction indicated by the arrow, shaft 80 will contact the latch 68 at point 88 and thus the head will be prevented from bypassing the latch. Further, any tendency for the latch 68 to become cammed, over a long period of time, and thereby render ineffective the latching action of the latch is effectively combated because the camming of the latch surface is such as to be complementary with the tapered surface 86 of the shaft 80. Shaft 80 acts a second actuating means as defined in the claims.

As stated above, the head latch 68 tends to move to its latching position whenever any of the racks are moved from the zero digit wheel position. However, of course, the latch cannot be permitted to move to its latching position until at least the printing cycle of the imprinter operation is performed. Thus, latch release means 90 is provided for preventing the latch 68 from moving to its latching position until the printing cycle of the imprinting operation is performed. Before proceeding with the detailed description of the latch release 90, the remaining details of the construction of the latch 68 will be described. As can best be seen in FIG. 4 the latch release 68 includes an inverted L-shaped portion. Disposed at the end of the shorter horizontal leg thereof is an inclined portion 92, which permits passage of the print head by the latch during the return cycle of the imprinting operation even though the latch is in its latching position, see FIG. 5. The vertical leg of the release 68 is rotatably mounted on head latch shaft 94 which can be seen in FIG. 4. Shaft 94 is connected at one end to a vertical leg 53 of the bracket 52 which extends from member 98 and at the other end to the interlock bracket 52, see FIG. 2, the bracket 52 being substantially U-shaped. As can be seen in FIGS. 3 and 5 a cylindrical projection 100 horizontally extends from the L-shaped portion concentric with the shaft 94. Cylindrical projection 100 is provided with a grooved section 102 as indicated in FIG. 3, this groove engaging a latch release finger 104 extending from the latch release 90.

The latch release 90 also includes an inverter L-shaped portion, the end of the horizontal leg being pointed as indicated in FIG. 5that is, the end includes two inclined surfaces 106 and 108, the slopes of which are opposite and which permit passage of the printing head during either the print or return cycle of the imprinting operation. The end of the vertical leg of the L-shaped latch release 90 is rotatably mounted upon a latch release shaft 110 which is cantilever mounted at one end thereof in interlock bracket 52 as shown in FIG. 2. A wire, latch release spring 112 connected at one end to the vertical leg of the latch release and wrapped around the shaft 110 and positioned under the member 98 as shown in FIG. 3 causes the latch release 90 to be constantly biased so that the horizontal leg thereof tends to extend into the path traversed by shaft 80.

Thus, the latch release 90 also can assume two positions the first of which corresponds to that shown in FIG. 3 where the latch release finger 104 is engaged in the groove 102 to thereby hold the latch in its second or non-latching position. The latch 68 Will be held in the position shown in FIG. 3 even though one of the racks is removed from the zero digit wheel position, which action as described hereinbefore tends to move the latch to its latching position. However, the latch release finger 104 will be disengaged from the groove 102 of portion 100 whenever the shaft 80 engages inclined surface 108 and forces the latch release 90 to assume its second or retracted position which in turn lifts finger 104 to thereby permit latch 68 to rotate forwardly into its latching position, assuming of course, that a counterclockwise moment is being applied to latch 68 because at least one of the racks 34a34f has been moved from the zero digit wheel position.

Having now described in detail the structure of a preferred embodiment of the invention, the operation thereof will now be discussed. Assume that the print head 70 is at the initial starting position. Prior to the imprintrng operation, the operator usually places a credit card or the like on a printing anvil, the card acting as a source of constant or fixed data. Next, he moves the racks to set in the printing bed variable information such as the amount of a sales transaction. As stated hereinbefore the translational movement of any of the racks 34a through 34 results in a tendency for the latch 68 to move to its latching position in the path traveled by the shaft 80, see FIG. 5. This force applied to the latch 68 results because of the engagement of the inclined surface 40 of the actuating rack against the inclined surface 42 of the interlock glide 44 which causes the bale 46 to move downwardly against the tension of bale spring 54, the bale being held in this downward position as long as any one of the racks is moved from the digit wheel position. As stated hereinbefore, the inclination of the surface 40 with the vertical is preferably approximately 30 degrees. It has been determined that this approximate inclination produces a downward force on the bale 46 of sufiicient strength so as to insure the movement of the latch 68 to its latching position when it is released by latch release 90. With the downward movement of the horizontal leg of bale 46, the flanged portion 58 at the end of the vertical leg 56 moves upwardly as indicated in FIG. 2 to force compression spring 64 against the horizontal leg of connecting link 60. Since the horizontal leg is connected into connecting arm 66 which in turn is connected to the vertical leg of latch 68 via portion 67 (see FIGS. 4 and 5) a force is applied to latch 68 tending to move it to its latching position.

However, latch release 90 will be in the position shown in FIG. 3 whenever the printing head is at the initial position and thus the mere movement of the racks to set the variable data in the printing bed will not cause the latch to be moved to its latching position. After the constant and variable data sources have been set in the printing bed, the first cycle of the imprinting operation commences and the head 70 is moved over the printing bed. The shaft 80 connected to the print head will not engage the latch 68 because the latch is in its retracted position; however, it does engage the inclined surface 108 of latch release 90 to thereby rotate latch release 90 clockwise as shown in FIG. 3 which in turn lifts finger 104 from groove 102 to thereby permit the movement of latch 68 to its latching position under the force of compression spring 64.

On the return cycle of the print head, the shaft 80 connected to the head will engage first the inclined surface 106 of latch release 90 thereby retracting the release slightly. As soon as the shaft 80 passes the apex of release 90, the release will spring forward under the control of spring 112. The shaft 80 will next engage the inclined surface 92 of latch 68 and the latch will be slightly retracted as the shaft passes by the latch. However, the inclination of surface 92 and the outermost projection of the latch 68 is such that the amount of retraction will be less than that required for groove 102 to engage the latch release finger 104 of latch release 90. Thus, after the print head 70 has been returned to its initial starting position, the latch 68 will be in the position shown in FIG. 5 to thereby prevent any further imprinting operation.

To effectuate the next imprinting operation, all of the racks 34a-34f must be returned to the zero digit wheel position. Thus, it can be seen that the herein described interlock effectively prevents the imprinter operator from performing another imprinting operation which would duplicate the prior imprinting operation. With the return of all of the racks to the zero digit wheel position, the latch 68 is returned to its non-latching position. This follows since all of the racks assume the position shown in FIG. 6 thereby permitting the horizontal leg of ink 46 to rotate upwardly around the bale shaft 48, which in turn causes flange portion 58 to move downwardly thereby pulling the connecting link 60 and the connecting arm 66 also downwardly to thereby retract latch 68 to its non-latching position, the latch being rotated about shaft 94. With all racks returned to the zero digit wheel position, the imprinting operation can once again be performed and the steps described again will once again occur.

Thus, it can now be seen that the aforedescribed illustrative embodiment of the invention eifectuates the objects and advantages claimed herein. In partciular, an interlock assembly is described which effectively and economically prevents the duplication of variable data set into the print bed of an imprinter unless all digit or print element setting means are returned to the zero digit 6 wheel or print element position between each imprinting operation.

Numerous modifications of the invention will become apparent to one of ordinary skill in the art upon reading the foregoing disclosure. During such a reading it will be evident that this invention provides a unique interlock assembly for accomplishing the objects and advantages herein stated. Still other objects and advantages and even further modifications will become apparent from this disclosure. It is to be understood, however, that the foregoing disclosure is to be considered exemplary and not limitative, the scope of the invention being defined by the following claims.

What is claimed is:

1. An imprinting device comprising:

aprint bed;

movable print elements positioned in said bed, all of said print elements including a common reference position;

means for setting said movable print elements in said bed;

a print head having a projecting member connected thereto and including a roller platen movable over said print bed in a first direction from a start position to effectuate an imprinting cycle and movable in the direction opposite said first direction to said start position during a return cycle of the imprinting operation;

movable latch means removably disposed in the path traveled by said projecting member for preventing the movement of the print head over the print bed when said latch means is in its latching posititon, said movable latch means permitting the passage of said printing head when retracted to its non-latching position;

latch release means removably disposed in the path traveled by said print head for holding said movable latch means in its non-latching position when said latch release means is in a first position, the holding action of said latch release means on said movable latch means being removed when said latch release means is moved to a second position;

first biasing means for normally biasing said latch release means in said first position;

first actuating means connected to said movable latch means and responsive to said means for setting the movable print elements;

second biasing means for normally biasing said first actuating means so that said movable latch means is in its non-latching position;

said first actuating means including a third biasing means for biasing said movable latch means toward its latching position against the holding action of said latch release means in response to at least one of said print elements being moved away from said common reference position;

said projecting member engaging said latch release means and moving it to its second position upon movement of said print head from its start position to effectuate an imprinting cycle whereby said latch means is moved to its latching position in response I to said third biasing means to thereby prevent said prirlit head from duplicating the said imprinting cyc e;

said first actuating means in response to the biasing action of said second biasing means returning said movable latch means to its non-latching position upon the movement of all of the print elements, which were initially moved from said common reference position, back to said common reference position.

2. An assembly as in claim 1 where said movable latch means has disposed at the end thereof an inclined surface which permits the passage of said projecting member of said print head during the return cycle of the imprinter operation even though said latch means is in its latching position.

'3. An assembly as in'claim 2 where said latch release means includes a latch release finger which'is biasedin a predetermined direction by said first biasing means connected between said latch release means and a fixed reference point, said movable latch means including a grooved portion which is engaged by said latch release finger when said latch release means is in its first position to thereby maintain the latch means in its non-latching position. I

4. An assembly as in claim 2 where said movable latch means is substantially L-shaped, the vertical leg thereof being responsive to said first actuating means.

5. An assembly as in claim 4 where saidlatch release means has disposed at the end thereof two inclined surfaces of opposite slope to thereby permit the passage of the projecting member connected to said'print held during both the imprinting and return cycles of the imprinting operation.

6. An assembly as in claim 1 where said first acutating means includes a U-shaped 'bale member, the horizontal leg thereof being biased by said second biasing means so as to be in engagement with the means for setting the print elements whenever any of said print elements are moved away from said common reference position.

7. An assembly as in claim 6 where said common reference position corresponds to the zero digit position.

j8.i" An assembly as in claim 7 where one of the vertical legs ofi'said U-shaped bale member has disposed approximately at one end thereof said third biasing means for actuating said movable latch means whereby the movement of one of said print elements away from the zero digit position causes said bale member to rotate thereby moving the said vertical leg thereof against said third biasingmeans thereby tending to move said movable latch means to its latching posititon as long as said one setting means is removed from said zero position.

9. An assembly as in claim 6 where said projecting member ,is tapered from the end thereof so that said movable latch means will be engaged by said projecting member at a point substantially removed from the end thereof.

. References Cited UNITED STATES PATENTS 3,138,091 6/1964 Maul 101-285 X 3,279,369 10/1966 Wight 101-269 3,322,062 5/1967 I Maul 101-45 3,334,582 8/1967 Mahoney 101 45 3,405,634 10/1968 Maul et a1. 101-45 WILLIAM B. PENN, Primary Examiner U.S. Cl. X.R. 101-269, 285 

